Image-based navigation applications and systems, collectively referred to herein as systems, have become a popular tool, and/or feature of map based navigation applications or systems, for visually simulating being in or traveling between locations within a geographic locality, such as cities, countries, etc. In one type of system, a computer displays to a user a simulated field of view using photographic images previously captured in a real-world geographic locality. As the user virtually navigates through a representation of the depicted geographic locality, such as by instructing the system to change their virtual location and/or to virtually “turn their head” or otherwise “look around,” the computer keeps up with the user's navigation and displays an updated simulated field of view which may include different photographic images taken from the real-world locality that represent the user's current location and/or point of view. Thus, an experience of actually looking around and/or moving through the represented locality may be evoked. One system for performing this kind of feature is disclosed in U.S. Pat. No. 7,688,229, the entire disclosure of which is incorporated by reference herein.
Image-based navigation systems, including those described above, typically utilize an image dataset which includes a collection of images and/or video which were previously collected by a set of one or more cameras carried through the geographic locality. The camera(s), which may be mounted on a vehicle or carried by a person, may take pictures (or video) in one or more directions or orientations as the vehicle or person moves. This method of capture may include the taking of numerous, overlapping pictures from several points of view, which allows the set of pictures to be post-processed, e.g. stitched or otherwise aggregated or composited together, to create substantially seamless panoramic images covering various fields of view at each location. These images may also be correlated with real-world geography, for example by gathering GPS or other geographic coordinate data and/or postal address data, along with camera orientation data and or date/time of collection, at the same time as the pictures are taken. This allows a user to specify, for example, a geographic location or a postal address, as well as an orientation/point of view, and then the navigation system may select and/or aggregate/composite the appropriate images from the image data set to present to the user a simulated field of view showing the specified geographic location from the user's chosen point of view. When a user specifies a starting location and a destination location within the geographic locality, the image-based navigation system may compute a navigation route, such as by using a map database, from the starting location to the destination location and then sequentially present, e.g. continuously or incrementally, appropriate images, or aggregates/composites thereof, selected from the image data set corresponding to locations along the route as the user virtually navigates the route, thereby providing the user with a simulated experience of travelling the route including being able to visually experience land marks, signs, store-fronts, display advertising and other points of interest, along and around the route.
As will be appreciated, during such virtual navigation, the user's attention may be focused on the route itself, e.g. they may be mentally preparing for, or in the process of, actually navigating the route. Some points of interest may lie outside the simulated field of view due to the orientation thereof during the simulated travel. Further, the sheer volume of visual information presented to the user via the various images may be substantial, such as when virtually navigating through dense urban localities. In addition, some visual details in the images may be obscured or indistinguishable due to the current perspective of the virtual point of view, e.g. in the direction of travel, or due to artifacts of the image capture or panoramic image creation processes. Accordingly, a user may consciously or subconsciously ignore, be blinded to, or otherwise miss or fail to see or appreciate a point of interest as they virtually “approach” or “pass by.”